Nonlinear structural models in cableway transport systems

In this paper an analysis of the nonlinear static behaviour of cable systems is developed by assuming a full nonlinear structural model of the cables based on elastic catenary results. The work is aimed at the possible application of this kind of structure to practical engineering systems such as among others ski lifts, electrical transmission lines, and cable systems in erection procedures of long-span bridges. The structural model is then implemented in a suitable computer code program able to analyse strong nonlinearities arising from low stress levels in the cables, where the uniqueness of the solution is not assured. Therefore, an appropriate simulation technique is required to capture the static equilibrium con®gurations of the cable systems subjected to a given external action. After a preliminary discussion of the relevant equations governing the behaviour of the structural model, a ®nite element analysis is developed to account for the main inherent features related to convergence and stability of the numerical algorithm used. Then, some illustrative numerical examples are developed by suitably calibrating the input data in such a way that strong nonlinearities stand out which enable the checking of the validity of the present analysis.